Question

I’m working on an .Net MVC3 project. I have the following code which runs 2 queries on the same table. The second query is depended on the results of the first. How can i rewrite this to use a single query (with nested query) and assign the results to my viewmodel?

public ViewResult Category(string id)
{
    var viewModel = new ProductCategoryNavigation();

    viewModel.category = db.Category.Single(c=>c.NavigationId==id);
    viewModel.subCategories = db.Category.Where(i => i.ParentId == category.Id);

    return View(viewModel);
}

Answer 1

var query = (from c in db.Category.Where(x => x.NavigationId == id)
             join sc in db.Category on c.Id equals sc.ParentId into g
             select new {
                 Category = c,
                 SubCategories = g
             }).Single();


viewModel.category = query.Category;
viewModel.subCategories = query.SubCategories;